1. Field, of the invention
The present invention relates to a looped yarn which is produced in such a way that a running yarn is led into an area of an eddy current of a pressurized fluid to form opened loops and closed loops on a surface of the yarn in that area. In more detail, the present invention relates to a latent looped yarn and a method for manufacturing the same, in which opened loops and closed loops are previously provided on the yarn and the latent loops are revealed after the latent looped yarn is woven into a fabric,, and a method for manufacturing the same.
The present invention also relates to a high density fabric made of latent looped yarn and having a spunlike touch.
2. Description of the Related Arts
Various looped yarns in which many fine opened loops and closed loops are provided on each respective component filament of a multifilament are used, since such a looped yarn has a characteristic of giving a fabric a voluminous feeling and a certain stiffness.
But many operational problems arise when using such looped yarns in a weaving process to make a fabric; for example, the yarn is hooked at an abrasive contacting portion of a guide or tensor to create an abnormal tension on the yarn, and thereby cause yarn breakage, or the element thereof is destroyed when spun yarns are used in the same process.
There are many kinds of brown looped yarns in which a plurality of fine opened loops and closed loops are provided on each respective component filament of a multifilament, for making a spunlike fabric utilizing multifilament yarns, and there have been many proposals for making such a yarn, since a fabric having a voluminous feeling and a certain stiffness can be produced by such yarns.
These kinds of yarn inherently have a significant drawback such that, when a high tension exceeding a level of tension required is applied to the yarn, the loops are eliminated and thus the voluminous characteristic given tot he yarn is lost. Also, the voluminous characteristic disappears because the opened loops and closed loops thereof are formed on the surface of the yarn only by an entanglement among the component filaments.
Further, Japanese Patent Publication 61-40778 discloses a method for manufacturing a napped fabric utilizing an interlaced and mixed multifilament yarn having a two-layer configuration in which a filament yarn having a high shrinkage ratio is used as a core yarn and ultra fine fibers entangled around the core yarn are used as a sheath yarn, and a technology in which a fabric woven or knitted with the yarn receives a napping treatment.
Generally speaking, a looped yarn as mentioned above is used in most cases as a weft yarn when producing a spunlike fabric with the looped yarn, because of the problems mentioned above, and heretofore, there has never been a case in which such a looped yarn is used as warp yarn of a fabric.
But, if a high density fabric is to be produced utilizing multifilament yarns, it is not sufficient to use such a looped yarn only as a weft yarn thereof, and such a looped yarn should be also used as a warp yarn. Nevertheless, when such a looped yarn is used as warp yarn of a fabric, other drawbacks arise such that, for example, when used as a warp yarn of a fabric, the warp yarn density must be extremely coarse, because of the entanglement of the looped yarns with each other on a loom, which causes a problem of a lowered shedding ability during a weaving operation, as well as the operational problems described above.
To solve these problems, many attempts, such as attenuating the denier of filaments of a sheath yarn, have been made, but these require the use of several kinds of supplemental devices for taking the looped yarn from a yarn package.
But even when such a supplemental device is used, the warp yarn density is limited, and thus a fabric having high warp yarn density can not be obtained thereby.
On the other hand, in order to improve the yarn taking up operation from a yarn package and to improve the yarn passage ability in a weaving or knitting process or a preparing process for making a fabric arranged before or after the above weaving or knitting process, or due to the restrictions imposed because, when such a looped yarn is used as a warp yarn of a fabric, such loops must be especially eliminated or the fabric as a final product must be woven by using a yarn having a small number of loops produced in such a way that the yarns are not provided with loops at a high density and large size thereon in the first stage of the yarn production, while making a difference between the yarn length of the component filaments of the yarn extremely small, so that a fabric having a satisfactory feeling and surface touch can not be obtained. Accordingly, at present such a looped yarn can not be used as a warp yarn for making a fabric having a relatively high yarn density.
As is well known in this field, the number of the loops and the size thereof in a conventional looped yarn are seldom changed or are slightly increased, even if such a looped yarn is subjected to a hot water treatment with a subsequent free tension, and if such a looped yarn were used as a warp yarn, it would be impossible to obtain a fabric having a high yarn density and good spunlike feeling.
Therefore, to make a spunlike fabric having a high yarn density, a looped yarn which can be used as a warp yarn must be realized.